(1) Field of the Invention
The present invention relates to an aircraft having an avionics system adapted in particular for withstanding lightning strikes. The invention is thus situated in the narrow technical field of systems that might be subjected to lightning strikes.
(2) Description of Related Art
An aircraft may include an avionics system, usually an avionics system including pieces of electronic and/or electrical and/or computer equipment connected together by wired connections, and in particular by electrical connections.
By its very nature, an aircraft is liable to be struck by lightning while in flight.
Such an impact generates indirect effects including generating transient electric currents flowing through the avionics system. Such a transient current possesses a high voltage and high energy.
Consequently, specifications for equipment in an avionics system may require a manufacturer to incorporate a protection system for providing protection against such transient currents.
In particular, avionics equipment may include a diode for suppressing transient voltages solely for the purpose of protecting the circuit. Such a diode may be considered to be a protective component of the surge suppressor type.
The avionics equipment is then protected against transient currents as predetermined by a specification.
Nevertheless, such transient currents may have characteristics that differ strongly from one aircraft to another.
In particular following a lightning strike, a transient current flowing in an avionics system of an aircraft having a metal structure differs from the transient current that would flow in an avionics system of an aircraft having a structure made of composite material.
Avionics equipment that is designed for an aircraft of metal structure is likely not to satisfy the specifications imposed for equipment on board an aircraft having a composite material structure.
This aspect can raise problems for a manufacturer, e.g. seeking to have uniform equipment installed over a wide range of aircraft.
At present, an aircraft manufacturer seeking to make an aircraft with a composite material structure can implement three different approaches.
The natural first approach consists in modifying the avionics equipment for a metal structure aircraft so as to enable it to be used on a composite material structure aircraft. The avionics equipment is modified so as to include a protection system against the levels of transient current that are to be expected on an aircraft with a structure made of composite material.
For example, the transient voltage suppressor diode of an avionics equipment may be replaced by a diode that corresponds to the new specifications.
This first approach is effective, but it can lead to costs that are relatively high. These costs include the costs of developing the new equipment, and also costs associated with managing new stock numbers specifying the new pieces of equipment.
Given the relatively large number of avionics equipment, these costs can thus be considerable.
A second approach consists in using pieces of avionics equipment that are not protected against the transient currents to which they might be subjected in flight, in particular as a result of a lightning strike.
In parallel, the manufacturer fits the avionics system with specific protection units connected in series in the wired connections. These protection units then include devices for protecting avionics equipment against destructive transient currents.
This second approach is also expensive, since it requires a plurality of protection units that are dedicated to protecting avionics equipment, which protection units are also heavy.
Like the second approach, a third approach consists in using avionics equipment that are not protected against the transient currents to which they might be subjected in flight.
In parallel, the manufacturer fits the wired connections of the avionics equipment with connectors that include devices for protecting the avionics equipment against destructive transient currents.
Such a connector thus seeks to suppress a transient current, and in particular to protect an avionics equipment that does not have its own protection.
Using such connectors can turn out to be expensive.
In particular, Document EP 0 512 927 B1 describes a set of transient current suppressor contacts. That set includes a multilayer thyristor having an active electrode and a ground electrode.
Document U.S. Pat. No. 5,846,099 does not belong to the technical field of avionics equipment to which the present invention relates. That Document U.S. Pat. No. 5,846,099 describes a connector having a diode-thyristor.
Document US 2013/171852 and Document EP 2 551 771 present avionics architectures.
Document US 2010/123591 presents a connector between two threaded ends. The connector includes an anti-explosion barrier and a printed circuit.
Document US 2003/0179533 describes a device for providing protection against voltage surges.
Also known is Document US 2010/127193.